HOUSING AND HYGIENE 



259 



individuals in the flock unless there is constant and positive 

 displacement of the expired air by fresh air. 



Fig. 134 



A poor poultry liouse; no ventilation. 

 Fig. 13o 



MakinH a noiiil pniiltry liouse out of a poor one (FiKure 134) l>y providing 

 ventilation by means of a cloth-curtain window and a straw loft. 



The need of ventilation is further emphasized bj' King,' 

 wlio quotes Calin as giving tlie cubic feet of air breathed liy 

 certain animals per thousand pounds of live weight as follows: 



Cow 

 Horse . 

 Hen 



2804 

 3401 



8278 



' Physics of Agriculture. 



